GPR39 marks specific cells within the sebaceous gland and contributes to skin wound healing.

G protein-coupled receptors (GPCRs) mediate multiple key biological processes in the body. The orphan receptor GPR39 has been reported to be involved in various pathophysiological events. However, the function of GPR39 in skin biology remains unknown. Using a genetically engineered mouse strain in which lacZ expression faithfully replaced endogenous Gpr39 expression, we discovered a unique expression pattern of Gpr39 in the sebaceous gland (SG). Using various methods, we confirmed that GPR39 marked a specific cell population at the opening of the SG and colocalised with the SG stem cell marker Blimp1. Further investigations showed that GPR39 was spatiotemporally expressed during skin wound repair. Although it was dispensable for skin development and homeostasis, GPR39 contributed positively to skin wound healing: its loss led to a delay in wound healing during the intermediate stage. The present study reveals a novel role of GPR39 in both dermatology and stem cell biology that has not been previously recognised.